HYDROGEOCHEMICAL CHARACTERIZATION OF ACID MINE DRAINAGE: OHIO VALLEY MUSHROOM FARM SITE IN NORTH LIMA, OH

A major concern associated with coal mining is the oxidation of minerals associated with coal, such as pyrite (Blowes et al., 2003). Pyrite oxidation is the principal cause of acid mine drainage (AMD), which can be characterized by a low pH and potentially high concentrations of iron, sulfate, manganese, calcium, aluminum, magnesium and several other elements (Blowes at al., 2003). This project serves as an evaluation of the geochemical and hydrologic properties of AMD at a site where both surficial and underground coal mining occurred, to detect any differences in the drainage resulting from source location. I hypothesize that there is a detectable geochemical difference between AMD that results from a surface or deep mine. The site chosen for this study is the Ohio Valley Mushroom Farm, located in North Lima, OH. The Mushroom Farm was chosen because underground and surface mining were both conducted on the property at separate times. After mining operations ceased the Ohio Valley Mushroom Farm was started. While mushroom farming was in progress, water was frequently pumped for mushroom production, inadvertently keeping the local water table down. When farming was shut down, the water pumping ceased and the water table rose with groundwater emerging from several seeps. Over the last 18 last 18 years, AMD has been leaving its mark on the Mushroom Farm. Winter and spring sampling of monitoring wells and wetland areas around the property were collected and analyzed via ion chromotography and spectrophotometry with a ferrozine assay. Temperature, pH, dissolved oxygen and conductivity were measured in the field with the use of a multimeter. Results indicate that water samples collected near a seep carry higher ferrous iron and sulfate concentrations than the rest of the sampled area. This seep is located in the downstream direction for groundwater flowing from the underground mine void. This indicates that the AMD resulting from the deep mine displays geochemical dissimilarities when compared to the AMD resulting from the surface mine spoil. Unlike much research that only focuses on surface mine spoil, this project compares hydrogeochemical analyses of surface mine spoil and an underground mine void. This is advantageous in the contributing to a future goal of producing geochemical signatures of AMD based on source location.